During production from a natural gas or oil well, it is not uncommon to hit pockets of fluid with significant sand content. Sand is highly undesirable for a number of reasons. Sand can fill the bore of the well; sand can fill the process system; or sand can simply diminish productivity of the well and/or production operation. Further, sand can cause undesirable wear of piping components, especially at elbows, or restrictions, as well as valves and differential pressure producers, such as orifice plates, venturies, or v-cones. Thus, the presence of sand during production from a natural gas or oil well can lead to pipe and valve erosion as well as the potential of failure of a variety of equipment used during production. Further still, sand flow can generate calibration shifts in the differential producers. Thus, it is very important during production from a natural gas or oil well that any sand flow be detected substantially immediately such that the problem can be addressed quickly and effectively, either locally at the production site, or remotely. This remedy may sometimes involve temporary shutting down the well, making adjustments to the well head operation, or changes to the well or field management (changes in injection, well depth, et cetera).
When the solids, entrained in the fluid, impinge upon production machinery, such as piping, valves, differential producers, et cetera, the impingement generates a sound. Generally the solids are sand and the fluid is a hydrocarbon fluid. However, other examples of solids entrained in fluid include slurries such as pulp stock, mining slurries, dredging slurries and sewage. It is known to sense sand in hydrocarbon production systems using acoustic sensors. Such sensors are generally dedicated devices that are tuned to the general frequency band within which the impingement's acoustic energy falls. While such devices are useful, they provide added complexity and costs to the overall production operation. Additionally, even state-of-the-art acoustic well sound detectors do not provide signaling that is easily integrated into an overall process measurement and control system.